A green four-legged creature who's insides are wired explosives. It stalks you, making no sound of its movement except the crunch of grass behind you until you turn to face the green monstrosity of which flashes white and ssSS's UNTIL- Boom. Then you lose your diamond pickaxe and respawn far from your location and slaughter millions of them in rage only to realize that.... It just wanted a hug.

Jimmy:HOLY ****! 3 DIAMOND ORE! -is beside lava-background creeper: sssssSSSSSSS.....
Jimmy:FFFUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU-
-explosion-
Jimmy: watches the spinning mini-block diamonds as they are engulfed by the lava in a fiery inferno, respawns and jumps off 4 story roof-

A green quadruped from the game Minecraft that is oddly shaped like male genitalia. These aggressive mobs, before exploding their victims into oblivion, hiss. The hiss is the only warning the player has of the creeper's presence, as creepers don't make sounds when they walk. The player then has approximately 1.5 seconds to vacate the range of the creeper before it has a chance to explode. When killed creepers drop sulfur (aka gunpowder).